The present invention is generally directed toward a new and improved apparatus for controlling the time cycle of vibratory finishing machines of the through-feed type wherein workpieces and finishing media are introduced at one end of an elongated vibratory tub or chamber and move longitudinally along the chamber during a finishing operation. When the media and workpieces reach the terminal or discharge end of the chamber, they are communicated to a separating apparatus wherein the media is separated from the workpieces and is recycled within the system by being communicated via a suitable conveyor belt to the inlet portion of the finishing chamber.
One particular problem of feed-through type vibratory finishing machines of the above-described type resides in the control of the time cycle during which workpieces are subjected to a finishing operation by the action of the finishing media within the finishing chambers. In particular, it has been found that when a long time cycle is desired, the discharge or outlet end or chute of the finishing chamber may be elevated slightly to resist the workpieces and media from traversing out the outlet end of the chamber; however, when this is done, the workpieces tend to hang up in the discharge chute due to the low media level at this point in the finishing chamber and additionally, there is a relatively small amount of finishing media available to be recycled via the return conveyor to the inlet portion of the finishing chamber. If it is desired to improve the discharge of the workpieces from the chamber, it has been necessary to lower the outlet end or discharge chute thereof and while this provides a relatively large amount of media for recycling via the return conveyor and greatly improved discharge characteristics, the time cycle for finishing the workpieces is reduced significantly and this can be highly objectionable in situations where a large time cycle is necessary in order to complete the finishing operation on the workpieces.
In accordance with the principles of the present invention, it has been found that a constant media flow can be maintained through the media return conveyor and the time cycle for the finishing operation can be varied in accordance with the desired time for finishing the workpieces by splitting or ratioing the media which is supplied from the return conveyor and transferring a first portion of such media to the inlet portion of the finishing chamber and a second portion of such media to a position adjacent the outlet or discharge end of the finishing chamber. As will hereinafter be described, by thus varying or proportioning the media supplied by the return conveyor between the inlet and outlet ends or zones of the finishing chamber, the desired time cycle can be achieved without varying the media level at the extreme discharge end or discharge chute of the finishing chamber which, in the past, has occurred and resulted in the workpieces being hung up within the chute when a long time cycle was desired.
It is accordingly, a general object of the present invention to provide a new and improved feed-through vibratory finishing machine.
It is a more particular object of the present invention to provide a new and improved time cycle control mechanism for feed-through type vibratory finishing machines.
It is yet a more particular object of the present invention to provide a new and improved vibratory finishing machine, as above described, which includes means for ratioing or proportioning the media supplied by the return conveyor between the inlet and outlet portions of the finishing chamber.
It is a more particular object of the present invention to provide a time cycle control mechanism, of the above character, which includes a proportioning gate or blade which may be manually adjusted to selectively ratio the media which is returned by the return conveyor between a first supply section which is communicable with the inlet portion or zone of the finishing chamber and a second supply section that is communicable with a secondary conveyor mechanism which communicates the media to a position adjacent the outlet end or zone of the finishing chamber.
It is still a further object of the present invention to provide a new and improved time cycle control device, of the above character, which is of a relatively simple design, is economical to manufacture and will have a long and effective operational life.